| 1. |
- Edblad, Thorsten, et al.
(författare)
-
Micro-topography of dental enamel and root cementum.
- 2009
-
Ingår i: Swedish dental journal. - : Swedish Dental Association. - 0347-9994. ; 33:1, s. 41-8
-
Tidskriftsartikel (refereegranskat)abstract
- The focus for the present study was to characterise dental enamel and cementum at the cervical region of healthy teeth by use of interferometry. The effect of a protein-dissolving enzyme, used for cleaning (Neutrase) on the surface topography, was also evaluated. Knowledge about the normal variation of surface topography of natural teeth is limited. In the design of artificial surfaces, intended to replace the function of lost biological surfaces, detailed knowledge of the latter is therefore of great importance. Nine health caries free premolars were used. The root cementum of three teeth was used for evaluation of Neutrase on the surface. On the six remaining teeth, the differences between the surface textures of enamel and root cementum were evaluated using 3D Interferometry. No statistical significant effect of Neutrase was identified. A significant difference between enamel and root cementum concerning surface topography using the different 3D parameters was recorded. When comparing values from the literature, the topography of artificial materials used in dentistry show similarities with the topography of the enamel and root cementum surfaces evaluated.
|
|
| 2. |
- Kanno, T., et al.
(författare)
-
Topography, microhardness, and precision of fit on ready-made zirconia abutment before/after sintering process
- 2007
-
Ingår i: Clin Implant Dent Relat Res. ; 9:3, s. 156-65
-
Tidskriftsartikel (refereegranskat)abstract
- Background Sintering porcelain on a ceramic abutment may change the microstructure and result in aging processes that influence the mechanical properties, internal strain, and the three-dimensional form of the abutment, thus causing a possible misfit between the abutment and the fixture. Purpose The aim was to investigate topography, microhardness, and precision of fit on yttrium-stabilized zirconia (Y-TZP) abutments before/after the sintering process. Materials and Methods Ten Y-TZP abutment samples were ground to a shape used in the clinical situation and divided at random into two groups: before/after sintering. After the surface roughness was measured on all abutments, the abutments were connected to fixture replicas, embedded in resin, and cut in the longitudinal axis. Both sides of the cut samples were measured with respect to microhardness and minimum distance between fixture and abutment surface. t-Test, one-way analysis of variance, and Bonferroni multiple comparisons were used to investigate statistical significant differences. Results The surface roughness (S(a) and S(dr)) after sintering was significantly higher than before sintering. The total average values of microhardness after sintering were statistically lower than before sintering with a difference of 2%. The total distance between abutment/fixture before/after sintering demonstrated no statistically significant difference. Contact between abutment/fixture was most common at the top area of the fixture. Conclusion A slight decrease of microhardness and contamination of porcelain particles immediately below the veneered part were found on the Y-TZP abutment after sintering. The sintering process did not affect the precision of fit.
|
|
